I also had this same problem -- the USB3 port suddenly stopped working on Mar 1. It was soon, but not immediately, after I updated my BIOS so it may or may not have had anything to do with that.

I just fixed it though by downloading and installing the most recent Fresco Logic xHCI Controller driver provided by Dell, under the Chipset category. This is version 3.5.46.0, dated 8/22/2012. Somehow the version I had installed was (if I remember correctly) 3.5.96.0, dated 11/2012. Although this was "newer" it also was not working. I have no idea how it got there since Dell doesn't provide that version, but installing 3.5.46.0 did fix it! Hope this helps other people.

I also am now having a problem - when I put the XPS 13 into "sleep" and pack it away over night, the next morning I get the "Windows has shut down unexpectedly" message. Anybody else seeing this? Related to the USB3 driver issue?

I also had this same problem -- the USB3 port suddenly stopped working on Mar 1. It was soon, but not immediately, after I updated my BIOS so it may or may not have had anything to do with that.

I just fixed it though by downloading and installing the most recent Fresco Logic xHCI Controller driver provided by Dell, under the Chipset category. This is version 3.5.46.0, dated 8/22/2012. Somehow the version I had installed was (if I remember correctly) 3.5.96.0, dated 11/2012. Although this was "newer" it also was not working. I have no idea how it got there since Dell doesn't provide that version, but installing 3.5.46.0 did fix it! Hope this helps other people.

Well - I did a lot of futzing around & got this <ADMIN NOTE: Substitute character removed as per TOU> working again. I'm not sure I would recommend this to everyone, but here's what i found.

The Fresco Logic USB3 Hub was using a 3.5.93.0 driver. I uninstalled that multiple times & it kept re-installing itself. I went into the Windows/System32/drivers folder and found 2 versions of the FLxHCI.sys driver. Go to the properties & look at the Details Tab. My 2 versions were 3.5.93.0 & 3.5.46.0. I deleted the .93 version. Restarted the machine a couple of times & it took the .46 version & seems to be working fine.

I had no option to roll back to 3.5.46.0, nor did un-installing the .93 version ever work.

This worked for me with a slight tweak. I also had the two drivers but on moving the .93 version out of the drivers folder and rebooting a couple of times the port was still inactive. What worked for me was to go to the device manager, select the Fresco ... Root Hub driver under the USB controller and manually update the driver from there. Going to Update Driver, and Browsing my computer to select the .46 driver caused the port to activate immediately.

Thank you for this suggestion. With Internet disabled, I uninstalled the driver -- asking Windows to delete the driver file. Windows then re-detected the USB hub, and installed the old driver for me. Without disabling Internet, Windows kept downloading the updated driver -- that does not work.

Thanks guys, this has worked for me too. Also just to let you know, Dell has been onsite (under warranty) trying to fix this issue on my Ultrabook. Dell replaced the motherboard and a few other bits and pieces, which of course did not work. The techy said I would have to reinstall the system software.

One thing that you need to be very aware of when it comes to device drivers. Keep tabs on what your Microsoft Update is doing, it may and will download OEM drivers which it thinks are newer and better then what your Vendor is supplying.

Here's an option for Windows 7/Vista users ( I have to check how to do this under Windows 8 because the way Microsoft changed access to "Group Policies" there's no more gpedit.msc on some version of Windows 8 :( which stinks in my opinion.

For Windows 7/Vista to prevent Microsoft Update from automatically installing what it thinks may be better/newer/updated drivers.

WARNING in regards to the next steps.

LIKE WARNINGS ABOUT REGEDIT.... DO NOT CHANGE ANY OTHER SETTINGS WHERE YOU DO NOT HAVE A COMPLETE UNDERSTANDING OF WHAT THE CONSEQUENSE MAY RESULT IN WHILE WORKING WITH GPEDIT (GROUP POLICIES). YOU CAN BREAK OR RESTRICT THE FUNCTIONALITY OF THE OS.

•Go to Start–>Search and type in gpedit.msc.

•Click the file found to open up the Local Group Policy Editor.

•Navigate to Computer Configuration->Administrative Templates->System->Device Installation and Click on the subfolder Device Installation on the left, on the right side you will see a list of possible restrictions.

•Right Click on Prevent Installation of Devices not described by other policy to edit this option. Set it to ENABLED.

•ENABLE Allow Administrators to override Device Installation Restriction policies at the top of the list as well.

Now, Windows won't automatically install drivers via Windows Update, but you can now manually install them yourself. Once you have the chance to google around and see if the drivers break anything of course. ;)

Windows 8 -- good question on how to set Group Policies on Windows 8 Home editions. Professional has GPEDIT, Home editions do not.

Cheers

EDIT: Forgot Windows 7 as well had restrictions on what versions come with GPEDIT - Only Windows 7 Professional, Enterprise and ultimate editions come with Group Policy Editor installed. But Google around on how to activate it in Home Premium, Home Basic, or Starter"